The long term goals of this research are (l) to study the cellular mechanisms that regulate the metabolism of glycoproteins and glycolipids, (2) to establish the means by which these compounds are incorporated into membranes and their relation to membrane biogenesis in general, and (3) to understand the relationship of glycoproteins and glycolipids to ascribed membrane functions such as regulation of cell growth, cell adhesion and intercellular recognition. We will determine which sugar nucleotides penetrate rat liver Golgi vesicles through a mechanism consistent with a protein carrier. The carrier protein will be purified and reconstituted with liposomes in order to determine its mechanism of action. We will further characterize CMP-NeuAc synthetase, a nucleoplasmic enzyme. Antisera and antibodies to the enzyme will be made and used to study whether it is synthesized on membrane bound or free ribosomes. Antibodies will also be used to determine (a) any differences in size, charge or processing between nascent chain and nuclear CMP-NeuAc synthetase, (b) the subcellular localization of the synthetase by means of microinjection of fluorescent labeled antibody into cells and (c) a possible function for the enzyme which could explain its unique localization as compared to that of other sugar nucleotide synthetases. We will continue with our studies of the intracellular transport of sialoglycoproteins, particularly from the Golgi to the plasma membrane.